The present invention relates to a liquid crystal display device. More particularly, the present invention relates to a liquid crystal display device which might be employed in mobile electronic equipments, which enables two-sided display, and which is moreover capable of achieving thin and light-weight devices.
Examples of conventionally suggested liquid crystal display devices capable of displaying images on both sides of a panel are those employing a method in which two separate liquid crystal panels are used, one on a front and on a rear or a method in which a pair of glass substrates is used wherein the substrates respectively serve as light-conducting plates.
However, both of the above methods were disadvantaged in that the thickness of the entire liquid crystal display devices became thick so that the subject of application thereof to mobile electronic equipments still remained. Particularly in the method in which glass substrates are employed as light-conducting plates, the two glass substrates needed to be of a thickness equivalent to light-conducting plates (approximately 1 mm) for allowing transmission of light into the interior of the glass substrates, and the thickness thereof was thus required to be approximately twice of the thickness of conventional glass substrates. This resulted not only in an increase of thickness of the liquid crystal panels but also in an increase of weight of a single glass substrate to as much as approximately 300 g (in case its thickness is approximately 1.1 mm) so as to lead to a drawback that the weight of the entire liquid crystal panels were increased. Another drawback was that the number of process steps was increased since liquid crystal panels, which were obtained by cutting glass substrates of large dimensions into desired dimensions, required processing of end surfaces through grinding or similar methods in order to make light incident from the end surfaces of the cut glass substrates.